Messages in this thread |  | | Date | Thu, 9 Jan 1997 19:11:38 -0500 (EST) | From | Wayne Ward <> | Subject | Re: Linux for JavaVM |
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It was design to run several MVS os. For example on a single CPU one could have a production system as well as a test environment. This allow a company from purchase a second CPU. Wayne
On Wed, 8 Jan 1997, John G. Alvord wrote:
> On Tue, 07 Jan 97 22:00:17 +1000, bofh@snoopy.virtual.net.au wrote: > > > > Running Linux in Linux in Linux would be a great thing! I've been reading > >reports about how IBM's older mainframes worked and specifically about the > >architecture of VM/DOS. Apparently they had a virtual machine which the OS ran > >in, the VM provided file access and linear memory to the OS. > I did a lot of work on that system, called VM. There was a control > program (CP) which ran virtual machines. It was all written in S/370 > assembler and was about 300K lines of code (VM and the user interface > called CMS which had a file system, an exec language, and little else). > Of course that excludes compilers, etc. > > Most of the work was a detailed simulation of memory and I/O. S/370 I/O > is complex, involving channel programs (you don't want to know). It also > simulated privileged instructions. The result was sufficient to run VM > under VM, which was a marvelous development environment. Imagine single > stepping, breakpointing, etc at the kernel level. > > A big project to duplicate. Incidently, VM still exists and is being > enhanced even today. > > john alvord >
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